JPH0973357A - Coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease signal lines connected to a vibration pen, to improve the operability of the vibration pen, and to reduce the electric power which drives the vibration pen as to the coordinate input device which inputs coordinates by giving vibrations to a vibration transmission plate. SOLUTION: A vibrator driving circuit 2 supplies a driving signal for a vibrator 4 to a ground level signal line 12. The signal line 12 is connected to the plus electrode of the vibrator 4 and a conductive pen tip 5 is connected to the minus electrode. Further, the top surface of the vibration transmission plate 8 is grounded. In this constitution, when the pen tip 5 of the vibration pen 3 is brought into contact with the vibration transmission plate 8, the minus electrode of the vibrator 4 is grounded and the driving signal is applied to the vibrator 4. Consequently, the vibrator 4 vibrates and its vibrations are inputted to the vibration transmission plate 8 through the pen tip 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device, and more particularly to a coordinate input device that applies a vibration to a vibration transmission plate to input coordinates.

[0002]

2. Description of the Related Art Conventionally, vibration is inputted to a vibration transmission plate by a vibrating pen having a vibrator such as a piezoelectric element, and transmitted through the vibration transmission plate by a plurality of vibration sensors provided on the vibration transmission plate. Each coming vibration is detected, and the distance between the vibration pen and each vibration sensor is calculated from the vibration transmission time,
There is known a coordinate input device that calculates the coordinates of a vibration input point from each calculated distance by a geometric calculation.

This type of coordinate input device has a timer for measuring the vibration transmission time from the input of the vibration by the vibrating pen to the detection of the vibration by each vibration sensor, and a drive for vibrating the vibrating pen. The timer is started at the timing of giving a signal, and the vibration transmission time to each vibration sensor is obtained from each count value at the timing when the vibration is detected by each vibration sensor.

Therefore, it was necessary to electrically connect the vibrating pen and the main body. The form of this connection is roughly classified into two types. One of them is a form in which a drive circuit that supplies a drive signal to the vibrator is provided on the main body side. In this case, the vibrating pen and the main body are formed by two signal lines, a ground line and a drive signal line. Connected. Another form is a form in which a drive circuit is provided on the vibrating pen side, and in this case, the vibrating pen and the main body are provided with a control signal line for controlling the drive circuit and three signals of a power line and a ground line. Connected by wires.

[0005]

However, if there are a plurality of signal lines connecting the vibrating pen and the main body as described above, the signal lines and terminals for connecting the signal lines are also required, resulting in an increase in cost. There was a flaw. Further, if the signal lines extend over a plurality of lines, the pen cord covering them becomes stiff and the handling of the vibrating pen becomes poor when inputting coordinates, which is not preferable in operation.

On the other hand, in order to make the vibrating pen cordless, it is necessary to incorporate a power source in the vibrating pen in the above coordinate input method, and as a result, the vibrating pen becomes heavier and larger and the operability is not always improved. In addition, in the cordless method, since the input coordinates are calculated from the difference in the distance from the vibration input position to each vibration sensor, the error increases in the process of calculation and the accuracy decreases. there were.

Further, in both cases, not only when the vibrating pen is actually in contact with the vibration transmitting plate to input coordinates, but also when the vibrating pen is not in contact with the vibration transmitting plate,
Since the vibrating pen is driven in a predetermined cycle, there is a problem that power is consumed unnecessarily.

The present invention has been made in view of the above problems, and an object thereof is to reduce the number of signal lines connected to a vibrating pen.

Along with this, it is another object of the present invention to improve the operability of the vibrating pen and to reduce the electric power for driving the vibrating pen.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and inputs a coordinate by bringing a vibrating pen, which vibrates by a vibrator having a pair of electrodes, into contact with a vibration transmission plate. A coordinate input device, comprising drive signal supply means for supplying a drive signal for the vibrator between the vibration input surface of the vibration transmission plate and one electrode of the vibrator, It has a pen tip portion electrically connected to the other electrode of the vibrator.

According to a preferred embodiment of the present invention, it is desirable to further comprise an input control means which is made of an insulating member which surrounds the tip portion of the pen and which exposes the tip portion of the pen by a predetermined pressure.

Further, for example, it is preferable that the input control means is an elastic insulating member that covers the tip portion of the pen, and has a projecting hole through which the tip portion of the pen projects by being deformed by a predetermined pressure.

Further, for example, the drive signal supply means is
It is preferable that the vibration input surface of the vibration transmission plate is grounded to supply the drive signal.

Further, it is desirable that the vibrator is a piezoelectric element.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment of the Invention] FIG. 1 is a diagram showing a configuration example of a coordinate input device according to the present embodiment. In the figure, the arithmetic control circuit 1 is a control circuit for controlling the entire coordinate input device, calculates the coordinates input by the vibrating pen 3, and outputs the coordinates to the display 11 or the like. The vibrator drive circuit 2 is a circuit that amplifies a pulse signal input from the arithmetic control circuit 1 and drives the vibrator 4 to vibrate the pen tip 5 of the vibrating pen 3. The drive signal line 12 causes the vibrator pen 2 to vibrate. 12 is electrically connected.

The vibration transmitting plate 8 is an aluminum plate, an iron plate,
It is a vibration transmitting plate made of a conductive metal member such as a SUS plate, or a glass plate or a resin plate having a conductive layer on the surface thereof, and is electrically grounded. The coordinates are input by bringing the vibration pen 3 into contact with a desired position in the effective area A on the vibration transmission plate 8. As will be described later, the vibrating pen 3 comes into contact with the vibration transmitting plate 8 and generates vibration in the pen tip 5 when a drive signal is applied, and this vibration causes the vibration transmitting plate 8 to vibrate.
To reach the vibration sensors 6a to 6d.

On the outer periphery of the vibration transmitting plate 8, a vibration isolator 7 is provided to prevent the reflected vibration from returning to the central portion.
Further, vibration sensors 6a to 6d such as piezoelectric elements for converting mechanical vibrations into electric signals are arranged at four corners around the vibration transmission plate.

The respective output signals from the vibration sensors 6a to 6d are sent to the preamplifier circuit (see FIG. 5), and the outputs amplified by a predetermined gain here are supplied to the signal waveform detection circuit 9. . Then, the signal waveform detection circuit 9 outputs a timing signal (Tg, Tp) indicating the timing at which the vibration has arrived. The arithmetic control circuit 1 obtains the vibration transmission time in each of the vibration sensors 6a to 6d from this timing signal,
The coordinates from which the vibration is input are calculated from them.

The display 11 is, depending on the embodiment,
It is a display provided behind the vibration transmission plate 8 which is a coordinate input unit, and is composed of, for example, a liquid crystal display, a CRT or their projection type display. Needless to say, when the display 11 is provided, the vibration transmission plate 8 should be formed of a transparent member having a conductive layer provided on the surface of a glass plate or a resin material plate.

The display drive circuit 10 is a drive circuit for displaying, on the display 11, coordinates or the like input by the vibrating pen 3 based on an instruction from the arithmetic control circuit 1. Hereinafter, details of each unit will be described.

<Example of Configuration of Coordinate Input Unit> FIG. 2 is a diagram showing an example of a driving mechanism of the vibrating pen. The arithmetic control circuit 1 is
The low-level pulse signal is supplied to the vibrator drive circuit 2, and the vibrator drive circuit 2 supplies a drive signal obtained by amplifying this pulse signal with a predetermined amplification factor to the vibrator 4 via the signal line 12. However, the oscillator 4 has a positive electrode side (in the drawing,
The upper electrode) is only connected to the drive signal output terminal of the vibrator drive circuit 2 by the signal line 12, and the minus electrode side (lower electrode in the drawing) is a pen tip made of a conductive material such as metal. 5 (vibration transmitting member).

As mentioned above, the vibration transmission plate 8 is grounded (at least the vibration input surface may have a grounded surface). Therefore, a drive signal is applied to the vibrator 4 when the pen tip 5 of the vibrating pen 3 contacts the vibration transmission plate 8, and the vibrator 4 is driven unless the pen tip 5 contacts the vibration transmission plate 8. Instead, power consumption can be suppressed as compared with the conventional configuration in which the vibrating pen 3 is constantly driven.

In this embodiment, a drive signal is applied to the vibrator 4 through the grounded vibration transmission plate 8 and the signal line 12. However, driving is performed by the potential difference between the signal line 12 and the vibration transmission plate 8. If the configuration applies a signal, it is not necessary to ground the vibration transmission plate 8.

FIG. 3 is a diagram showing an example of the configuration of the pen tip portion of the vibrating pen. In this example, a piezoelectric element is used as the vibrator 4. The signal line 12 is connected to the oscillator 4 on the positive (+) electrode side. It suffices to make this connection electrically. For example, the signal line 12 may be fixed with solder or the like, or the conductive member may be biased with a spring or the like to be pressed into contact. A pen tip 5 (vibration transmitting member) made of a conductive material such as metal is connected to the minus (-) electrode side. Since this connection applies a drive signal, it requires an electrical connection and at the same time a mechanical connection that functions as a vibration transmission member for transmitting vibration.

Therefore, it is desirable to use a conductive adhesive to sufficiently make electrical contact between the pen tip 5 and the vibrator 4, but the vibrator 4 and the pen 5 are pressed with sufficient pressure. If it can be attached and fixed while maintaining electrical contact, it may be fixed with an adhesive having no conductivity.
Further, if the same connection as described above can be obtained, crimping may be used.

In order to efficiently transmit the vibration of the vibrator 4 to the vibration transmitting plate 8, the pen tip 5 preferably uses a member having a pointed end other than a conical shape or a horn shape, for example. Further, as described above, at least the tip of the pen tip 5 is in contact with the conductive vibration transmission plate 8 and is electrically conductive with the negative electrode of the vibrator 4, so that the conductive material such as metal is used. It is composed of members. The pen tip 5 is, for example,
The whole may be formed of a conductive member, or if the negative electrode of the vibrator 4 and the vibration transmission plate 8 can be electrically conducted, as shown in (b), a resin material is used. The surface of the non-conductive member (insulating member) may be covered with a conductive material, or the axis center may be formed of a conductive material as shown in (c), or another structure having the same function. May be As described above, there is a degree of freedom in the configuration of the pen tip 5, and an appropriate configuration can be selected according to the desired shape, vibration characteristics, and the like.

When the pen tip 5 comes into contact with the vibration transmission plate 8 and a drive signal is applied to the vibrator 4, the drive signal (electrical signal) is converted into mechanical ultrasonic vibration, and the pen tip is 5
Is transmitted to the vibration transmission member 8 via. The oscillator 4
It is desirable to select a value capable of generating a plate wave in the vibration transmission plate 8 as the vibration frequency generated by the above. Itami
It has the advantage that it is less susceptible to scratches, obstacles, etc. on the surface of the vibration transmission plate than surface waves. Furthermore, oscillator 4
By making the vibration frequency generated by the resonance frequency of the vibration transmission member (including the pen tip 5 and the vibration transmission plate 8), it is possible to efficiently perform the vibration conversion.

<Arrangement Example of Arithmetic Control Circuit> Arithmetic control circuit 1
Has a built-in timer circuit, and the timer circuit is activated at a timing of outputting the above-mentioned pulse signal to the oscillator drive circuit 2 at every predetermined cycle (for example, every 5 msec), and the timer circuit is generated in accordance with the pulse signal. Timing signals (Tg, Tp) indicating that ultrasonic vibration (generated when the vibration pen 3 is in contact with the vibration transmission plate 8) propagates through the vibration transmission plate 8 and reaches each of the vibration sensors 6a to 6d. The detection is performed, and the group delay time tg and the phase delay time tp for each of the vibration sensors 6a to 6d are obtained from the count value.

Then, from these vibration transmission times, the respective vibration transmission distances from the vibration input position to the respective vibration sensors 6a to 6d are calculated, and geometric calculation is performed from the calculated respective vibration transmission distances to input. Calculate the coordinates.

Further, the arithmetic control circuit 1 drives the display drive circuit 10 based on the calculated input coordinates,
The display on the display 11 is controlled and the input coordinates are output to an external device by serial communication, parallel communication, or the like.

FIG. 4 is a block diagram showing a configuration example of the arithmetic control circuit 1. In the figure, a microcomputer 31 is a microcomputer that controls the entire coordinate input device, and includes a ROM that stores the following control procedures, a RAM that functions as a work memory when performing calculations, and a reference that is used during control. It is configured by a non-volatile memory or the like that stores constants (including constants for correcting vibration transmission time) and the like.

The timer 33 is a timer (for example, composed of a counter) that operates in accordance with a reference clock (not shown), and starts when the above-mentioned pulse signal is supplied to the vibrator drive circuit 2. Starts timing operation as a signal. This makes it possible to synchronize the start of time measurement by the timer 33 and the vibration input by the vibrating pen 3 and measure the respective delay times until the vibration is detected by the vibration sensors 6a to 6d. In addition,
As described above, the drive signal is actually applied to the vibrator 4 by the vibrator drive circuit only when the pen tip 5 is in contact with the vibration transmission plate 8.

The timing signal (Tg, Tp for each vibration sensor) of vibration arrival for each of the vibration sensors 6a to 6d, which is input from the vibration waveform detection circuit 9, is processed into a latch signal by the detection signal input circuit 35. And input to the latch circuits 34a to 34d. Latch circuits 34a to 34
d corresponds to the vibration sensors 6a to 6d, respectively, and timing signals (Tg, Tp) related to the corresponding vibration sensors.
Upon receipt of, the latch circuits 34a to 34d latch the output (clock value) of the timer 33 for each of the timing signals (Tg, Tp).

Then, the judgment circuit 36 detects that all the timing signals (Tg and Tp × 4 sensors) have been received, and based on this, the latch circuits 34a to 34d detect the measured values of the respective vibration sensors 6a to 6d. That is, the vibration transmission time (tg, tp) is read, and the coordinates at which the vibration is input are calculated based on the read time. The calculated coordinate values are
For example, dots can be displayed at corresponding positions on the display 11 via the I / O port 37. Also, it can be output to an external device by being supplied to an interface circuit (not shown) via the I / O port 37.

<Measurement Example of Vibration Transmission Time> An example of measurement of the vibration transmission time from the vibration input position to each of the vibration sensors 6a to 6d will be described below. FIG. 5: is a figure which shows an example of the signal waveform regarding measurement of a vibration transmission time. The vibration sensor 6a will be described below, but the same applies to the other vibration sensors 6b to 6d, and the circuits provided corresponding to the vibration sensors 6a to 6d operate in parallel.

The vibration transmission time from the vibration input position to the vibration sensor 6a is measured by the vibrator drive circuit 2 as described above.
When the pulse signal is supplied to, the timer 33 is started by using it as a start signal. At this time, if the pen tip 5 of the vibration pen 3 is in contact with the vibration transmission plate 8, a drive signal is applied to the vibration pen 3 (vibrator 4) and vibration is input to the vibration transmission plate 8. Therefore,
When the pen tip 5 is not in contact with the vibration transmission plate 8, naturally, the intended vibration cannot be detected by the vibration sensors 6a to 6d. Therefore, input is performed until the pen tip 5 contacts the vibration transmission plate 9. It is not necessary to calculate the coordinates. Hereinafter, a case where vibration is properly input to the vibration transmission plate 8 will be described.

Ultrasonic vibration (signal 41 is a drive signal or a pulse signal) properly input to the vibration transmission plate 8 travels over a vibration transmission time corresponding to the vibration transmission distance from the input position to the vibration sensor 6a. Then, it is detected by the vibration sensor 6a. The signal 42 indicates a detection signal detected by the vibration sensor 6a.

Since the vibration used in this embodiment is a plate wave, the relationship between the envelope 421 and the phase 422 of the detection signal 42 changes during the transmission of the vibration in accordance with the transmission distance. Here, the traveling speed of the envelope 421, that is, the group velocity is Vg, the traveling speed of the phase 422,
That is, the phase velocity is Vp. The arithmetic control circuit 1 is
Using this known group velocity Vg and phase velocity Vp, the vibration transmission distance between the vibration pen 3 and the vibration sensor 6a can be calculated from the vibration transmission time.

First, focusing only on the envelope signal 421, its speed is Vg, and the envelope signal 42
A predetermined point 1 such as an inflection point or a peak point is detected, and the time from the input of vibration to the detection, that is, the group delay time is tg.
(See signal Tg), the vibration pen 3 and the vibration sensor 6
The approximate distance d ′ from a is given by d ′ = Vg · tg (Equation (1)). Note that the equation (1) can be used to similarly calculate the vibration transmission distances for the other three vibration sensors 6b to 6d.

Further, in order to determine the coordinates with higher accuracy, processing based on the detection of the phase signal 422 is performed. For example, the time from the input of vibration to the zero cross point of the phase signal 422 after the envelope signal 421 exceeds the predetermined threshold signal 46, that is, the phase delay time is tp (see the signal Tp; a window of a predetermined width with respect to the signal 47). (Obtained by generating the signal 44 and comparing it with the phase signal 422),
The distance d between the vibration pen 3 and the vibration sensor 6a is expressed by the following equation: d = n · λp + Vp · tp (2) However, λp is the wavelength of the elastic wave and n is an integer. Here, when d ′ = d, the integer n is expressed as n = [(Vg · tg−Vp · tp) / λp + 1 / N] (3). However, N is a real number other than "0",
Use an appropriate value. For example, when N = 2, n can be determined (that is, a region having continuity in the equation (2) can be determined) if the variation of tg or the like is within ± 1/2 wavelength.

By substituting the value of n obtained from the equation (3) into the equation (2), the distance between the vibrating pen 3 and the vibration sensor 6a is calculated using the phase delay time tp which is discontinuous but has high accuracy. d can be measured accurately. The signal waveform detection circuit 9 generates the timing signals Tg and Tp for measuring the group delay time tg and the phase delay time tp, which are vibration transmission times. Hereinafter, a configuration example of the signal waveform detection circuit 9 will be described.

FIG. 6 is a block diagram showing a configuration example of the signal waveform detection circuit 9. In the figure, the output signal of the vibration sensor 6a is amplified by the preamplifier circuit 51 at a predetermined amplification factor. The amplified signal is passed through the bandpass filter 511.
Removes excess frequency components (corresponding to signal 42),
For example, the envelope signal (corresponding to the signal 421) is input to the envelope detection circuit 52, which is configured by an absolute value circuit, a low-pass filter, and the like, and is extracted. The envelope / peak detection circuit 53 differentiates the extracted envelope signal twice, for example, to generate a signal indicating the peak of the envelope (twice differentiated signal), and supplies the signal to the Tg signal generation circuit 54. The Tg signal generation circuit 54 is composed of, for example, a monostable multivibrator or the like, generates a gate signal of a predetermined width from the twice-differential signal, and envelopes the zero-cross point of the twice-differential signal in the period when the gate signal is open. The signal Tg which is the detection signal of the peak point of is generated. The signals Tg generated based on the signals detected by the vibration sensors 6a to 6d are
Signals Tga to Tgd (input signal of the arithmetic control circuit 1).

The trigger signal detection circuit 55 includes an envelope signal (signal 42 detected by the envelope detection circuit 52.
A pulse signal (corresponding to the signal 47) of a portion where the value corresponding to 1 exceeds a predetermined level (corresponding to the threshold signal 46) is generated. The monostable multivibrator 56 includes the trigger signal detection circuit 5
A gate signal (corresponding to the signal 44) having a predetermined time width triggered by the pulse signal generated in 5 is generated. Tp
The signal generation circuit 57 is configured by, for example, a comparator, and performs pulse conversion on the output signal (corresponding to the signal 422) of the bandpass filter 511 during the period when the gate signal input from the monostable multivibrator 56 is open, and the phase A signal Tp which is a signal detection signal is generated. The signals Tp generated based on the signals detected by the vibration sensors 6a to 6d are changed to signals Tpa to Tpd.
(Input signal of the arithmetic control circuit 1).

As described above, the arithmetic control circuit 1 has the signal T
g (Tga to Tgd) and signal Tp (Tpa to Tpd)
From the vibration input position, each vibration sensor 6
Each vibration transmission time from a to 6d (group delay time tg,
The phase delay time tp) can be obtained.

<Circuit Delay Time Correction Example> The time value latched in the above-mentioned latch circuits 34a to 34d, that is, the vibration transmission time is the vibrator drive circuit 2 and the vibration sensor 6.
(6a to 6d), signal waveform detection circuit 9, arithmetic control circuit 1
Delay time e due to propagation delay of electrical signals in
t and the phase offset time toff. These errors are constant regardless of the path from the vibration pen 3 to the vibration sensor 6 (6a to 6d) via the vibration transmission plate 8, that is, regardless of the vibration input position.

Therefore, for example, the distance from the origin O in FIG. 7 to the vibration sensor 6a is set to R1, vibration is input to the origin O with the vibrating pen 3, and the measured value of the vibration transmission time from the origin O to the vibration sensor 6a is measured. Tgz '(group delay time), tp
z ′ (phase delay time), and vibration sensor 6a from the origin O
Assuming that the true vibration transmission time is up to tgz and tpz, the relationship between the circuit delay time et and the phase offset toff is: tgz '= tgz + et (4) tpz' = tpz + et + toff (5) Given in. On the other hand, the actual measurement values tg ′ and tp ′ at arbitrary input coordinates P (x, y) are as follows: tg ′ = tg + et (Equation (6)) tp ′ = tp + et + toff (Equation (7)) Here, the difference between the formulas (4) and (6) and between the formulas (5) and (7) is: tg'-tgz '= (tg + et)-(tgz + et) = tg-tgz Formula (8) tp′−tpz ′ = (tp ′ + et + toff) − (tpz + et + toff) = tp−tpz Equation (9) is obtained, and the circuit delay time et and the phase offset toff included in each transmission time are removed. Furthermore, equation (8)
By modifying (9) and (9), tg = tg '+ (tgz-tgz') ... Equation (10) tp = tp '+ (tpz-tpz') ... Equation (11). Here, tgz and tpz are equations (1) to (3).
Is a value that can be theoretically calculated from tgz ', t
pz ′ is a value that can be actually measured and obtained at the time of shipment, and these values are stored in a non-volatile memory or the like provided in the microcomputer 31 to use Equations (10) and (11). The group delay time tg and the phase delay time tp are corrected, and the results can be used to calculate the vibration transmission distance more accurately than in equations (2) and (3). The same applies to the other vibration sensors 6b to 6d.

<Example of Calculation of Coordinates> Next, from the vibration input position calculated based on the above-mentioned example, each of the vibration sensors 6a ...
An example of calculating the input coordinates of vibration using each vibration transmission distance up to 6d will be described.

FIG. 7 is a diagram for explaining an example of calculation of vibration input coordinates. In the figure, P (x, y) is the input coordinate of the vibration. Further, da to dd are the input coordinates P of the vibration.
It is the vibration transmission distance of each of the vibration sensors 6a to 6d from (x, y), and can be calculated by the arithmetic control circuit 1 according to the above-described example. Then, the arithmetic control circuit 1 further calculates the input coordinates P (x, Y) based on da to dd. When the distance between the vibration sensors 6a-6b is X and the distance between the vibration sensors 6a-6c is Y, the input coordinate P of the vibration is P.
(X, y) is given by x = (da + db) * (da-db) / 2X ... Equation (12) y = (da + dc) * (da-dc) / 2Y ... Equation (13) . Thereby, the arithmetic control circuit 1 can calculate the input coordinate of the vibration in real time.

Equations (12) and (13) are examples of calculating the coordinates based on the respective vibration transmission distances measured by the three vibration sensors, but by providing at least two vibration sensors. The coordinates can be calculated. Further, the arrangement of the vibration sensors is not limited to the above example, and for example, four vibration sensors may be arranged in a cross shape at the center of the side.

In the above example, the vibrator driving circuit is provided on the main body side, but the vibrator driving circuit may be built in the vibrating pen side. In this case, by providing the ground potential from the vibration transmitting plate as described above, the signal line connected to the vibrating pen has two lines, a control line for controlling the vibrator driving circuit and a power line. be able to.

As described above, according to this embodiment, the ground wire connecting the main body and the vibrating pen can be eliminated. As a result, the number of signal lines included in the pen code can be reduced, so that the pen code can be softened and the handling (operation) of the vibrating pen becomes easy.

Further, the manufacturing cost of the pen cord and its connecting terminal can be reduced.

Further, since the drive signal is applied to the vibrator only when the pen tip of the vibration pen is brought into contact with the vibration transmission plate, that is, when the coordinates are input, the power consumption for driving the vibrator is reduced. be able to.

Further, in the cordless system, since the input coordinates are calculated from the difference between the respective distances from the vibration input position to each sensor, the error increases in the process of calculation and the accuracy deteriorates. According to the above, the operability can be improved while maintaining the accuracy of the coordinate calculation.

[Second Embodiment of the Invention] In the first embodiment, the vibrating pen 3 has a conductive tip portion exposed. However, in the present embodiment, the brush is used. A configuration will be described in which the conductive tip of the vibrating pen 3 projects and is electrically connected to the vibration transmitting plate 8 (a drive signal is applied) by applying pressure. , Fig. 8
FIG. 4 is a diagram showing a configuration example of a vibrating pen according to the present embodiment. In the figure, (a) shows a state in which the pen pressure is not applied to the vibrating pen 3, and (b) shows a state in which the pen pressure is applied to the vibrating pen 3. Reference numeral 13 denotes an insulating clothing member provided on the surface of the tip portion of the pen tip 5 and made of a viscoelastic material or a material such as a resin that has elasticity and is deformed by pressure.
The tip of the pen tip 5 is provided with a notch or a hole. The notch or the hole is deformed by the writing pressure, and the tip of the pen tip 5 and the vibration transmitting plate 8 can be brought into electrical contact with each other.

When the coordinates of the insulating clothing member 13 are not input, that is, when the tip portion (pen tip 5) of the vibrating pen 3 is not in contact with the vibration transmitting plate 8, the insulating clothing member 13 is set as shown in (a). , The state in which the tip of the pen tip 5 is covered (in this state, the vibrator 4 is not driven because the ground potential is not supplied to the vibrator 4). On the other hand, at the time of inputting the coordinates, by pressing the tip of the vibrating pen 3 against the vibration transmitting plate 8, the insulating clothing member 13 is deformed by the writing pressure at the tip. The insulating covering member 13 is a covering member 13.
The notch or the periphery of the hole provided at the tip of the vibrating pen 3 is partially pushed outward, and the tip of the vibrating pen 3 is deformed so as to project. When the writing pressure exceeds a certain value, the insulating clothing member 13 is further deformed, and the tip of the vibrating pen 3 comes into contact with the vibration transmitting plate 8 as shown in FIG. The electrode side and the vibration transmission plate 8 are in electrical contact with each other and a drive signal is applied thereto.

As described above, since the insulating clothing member 13 is deformed by frequent application of pressure, it is necessary to select a material having resilience capable of withstanding repeated deformation.

The above construction is an example in which an insulating clothing member is provided on the pen tip, but the present invention is not limited to this, and by applying a writing pressure of a certain value or more,
For example, the same effect can be obtained in a structure in which the electrode of the vibrator and the vibration transmitting plate are electrically contacted by the deformation of the elastic member such as the spring.

With the above configuration, even when the vibrating pen is accidentally brought into contact with the vibration transmitting plate, the vibrator is not driven unless the contact pressure exceeds a predetermined pressure. Therefore, the vibrator is driven. Power consumption can be suppressed. Moreover, since vibration does not occur unless a predetermined writing pressure is applied, it is possible to stably input coordinates.

The present invention may be applied to a system composed of a plurality of devices or a single device. Further, it goes without saying that the present invention can be applied to the case where it is implemented by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or device, the system or device
It works in a predetermined way.

[0062]

As described above, according to the present invention, it is possible to reduce the number of signal lines connected to the vibrating pen.

In addition to this, there is an effect that the operability of the vibrating pen can be improved.

In addition to this, there is an effect that the electric power for driving the vibrating pen can be reduced.

[0065]

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration example of a coordinate input device.

FIG. 2 is a diagram showing an example of a driving mechanism of a vibrating pen.

FIG. 3 is a diagram showing a configuration example of a pen tip portion of the vibrating pen according to the first embodiment.

FIG. 4 is a block diagram showing a configuration example of an arithmetic control circuit.

FIG. 5 is a diagram showing an example of a signal waveform relating to measurement of vibration transmission time.

FIG. 6 is a block diagram showing a configuration example of a signal waveform detection circuit.

FIG. 7 is a diagram illustrating an example of calculating input coordinates of vibration.

FIG. 8 is a diagram showing a configuration example of a vibrating pen according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arithmetic control circuit 2 Oscillator drive circuit 3 Vibration input pen 4 Oscillator 5 Pen tip vibration transmission member 6a-6d Vibration sensor 7 Anti-vibration material 8 Vibration transmission plate 9 Signal waveform detection circuit 10 Display drive circuit 11 Display 12 Drive signal line 13 Insulating coating members

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Ryozo Yanagisawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Katsuyuki Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A coordinate input device for inputting coordinates by bringing a vibrating pen, which generates a vibration by a vibrator having a pair of electrodes, into contact with a vibration transmission plate, the vibration input surface of the vibration transmission plate and the vibrator. Drive signal supply means for supplying a drive signal for the vibrator between the electrode and one of the electrodes, and the vibrating pen has a pen tip electrically connected to the other electrode of the vibrator. A coordinate input device characterized by. 2. The coordinate input device according to claim 1, further comprising an input control unit that is made of an insulating member that surrounds the tip of the pen and that exposes the tip of the pen by a predetermined pressure. 3. The input control means is an elastic insulating member that covers the tip portion of the pen, and has a projecting hole through which the tip portion of the pen projects by being deformed by a predetermined pressure. The coordinate input device according to 2. 4. The drive signal supply means supplies the drive signal by grounding a vibration input surface of the vibration transmission plate. Coordinate input device. 5. The coordinate input device according to claim 1, wherein the vibrator is a piezoelectric element.